Incandescent electric lamp and method of manufacture



April 14, 1942. gE T N 1 2,279,871

INCANDESCENT ELECTRIC LAMP. AND METHOD OF MANUFACTURE Filed Dec. 1, 1939 ATTORNEY Patented. Apr. 14, 1942 INCANDESCENT ELECTRIC. LAMP AND METHOD OF MANUFACTURE Stanley H. Newton, Bloomfield, N. 1., asslgnor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa... a corporation of Pennsylvania Application December 1, 1939, Serial No. 307,095

8 Claims.

This invention relates to incandescent electric lamps, the method of manufacture and, more particularly, togas-filled miniature lamps of high candle power and low voltage, in which a reflecting coating is placed on part of the surface of the lamp bulb to direct-radiations emitted by the filament.

An object of my invention is the provision of means for preventing overheating of the arbor,

fleeting coating.

Referring to the drawing in detail, like parts being designated by like reference characters, there is shown, as one embodiment of my invention, an incandescent electric lamp ll of what is designated as a miniature type; that is, the

bulb i2 is desirably relatively small or about the size of that of an automobile headlight. In the present embodiment, I have shown a lamp in which the bulb l2, desirably of glass, is filled with an inert gas, such as argon, and the mount holds a coiled tungsten filament 13 of the one-hundred candle-power size, adapted for operation at a potential of 32 volts. It will, of course, be unor portion of the bulb adjacent the filament which derstood that these figures are merely illustrative may serve as a support for the same, during opand not limiting, eration of the lamp, especially where the fila- The bulb 52 has sealed thereto a glass flare ment is carried close to a portion of said suptube It terminating in a press 95. Through the port, press extend lead-in conductor supports it and Another object of my invention is the provision 25 ii, the former electrically connected to the shell of an incandescent electric lamp having a bulb, i8 oi the base it, and the latter to the center of the so-called miniature size, and an arbor car-- contact 23 of said base. rying an incandescible fllament,wherebysaid nla- Between the conductor supports it and H exment is disposed close to said arbor, and means tends a glass arbor. 22 terminating in a button coating that portion of said arbor adjacent said 23, preferably having a convex or globular outer filament to prevent overheating. or end surface. From the button, or the present A further object of my invention is the proembodiment, extend relatively short filament supvision of'an incandescent electric lamp in which ports 26, 25 and 26 terminating in loopsZl, 28 a specular metal coating, such as aluminum powand 29. The filament It has its ends secured, der mixed with a nitrocellulose, or Bakelite var- 25 respectively, to the conductor supports it and H, nish binder, is painted on the button of the stem, its intermediate portions passing through the carrying a high candle power tungsten coil beloops 2i, and 29, so that it is properly suptween supports, in order to reflect at least some ported in the desired position. of the heat from said button and prevent melt- On account of the high candle power of the ing thereof, the coating selected being desirably 30 filament and the nearness to the button 23, the of such a character that it also acts as a getter latter 'is very apt to become overheated and melt and helps to prevent bulb-blackening. in operation. In order to avoid this undesirable A still further object of my invention is the result, I apply to the button a reflecting coating manufacture of miniature incandescent electric 3|, preventing the absorption of radiant energy lamps of high candle power in which the filato as great an extent as possible. Although variment-carrying part is protected from overheatous coatings may be employed, such as silver or ing by an energy-reflecting coating which also other material which has high reflecting characdesirably functions as a getter. teristics, I prefer to usealuminum powder mixed Other objects and advantages of the invention, with a nitrocellulose or Bakelite varnish binder, relating to the particular arrangement and con- 40 which is then painted on the button between the struction of the various parts, will become appoints of connection with the supports 24, 25 parent as the description. proceeds. and 26, as shown most clearly in Figure 2, de-

Referring to the drawing: sirably leaving uncoated portions 32 of the outer Figure 1 is an enlarged side elevational view, suri'ace, around the points where the supports partly in vertical section, of a lamp embodying enter the button, in order to prevent shunting my invention. of any current through the coating.

Figure 2 is a further enlarged view of a portion Experiments show that in a lamp of the charof the mount, of the lamp of Figure 1, adjacent acter described, without the reflecting coating the stem button, showing how the filament supdisclosed, the excessive heatfrom the high candle ports extend therefrom and the extent of the repower filament was such that, upon burning, the

button blackened or melted. Upon applying the aluminum paint to such a button, it was found that the same was so protected that melting and undesirable results, such as bulb blackening, were avoided.

' button,

on the inside oi the lamp bulb, as on the relatively iargearea oi the arbor button or. other filament-supporting portion, said reflecting material being silver or aluminum, so as to not amasri 4. In an incandescent electric lamp. a bulb, a

. flare tube sealed therein and havin a press, leadonly augment the light cutput ot the lamp by reflecting a beam,'and prevent the portion which carries the reflecting surface,

but also cooperate with the tungsten filament and gas filling to reduce blackening of the lamp bulb and increase the life 0! the lamp.- I thus substantially prevent blackening oi the bulb th ughout the life of the filament.

Although .a preferred embodiment of my invention has been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims.

This application my application Serial No'. 215,845, filed June 23, 1938, tor the improvement in Incandescent electric lamp ,and method oi manufacture, and owned by the assignee of the present application.

I claim:

1.- An incandescent electric lamp comprising a bulb, ton at its iree end and integral therewith, a filament supported from said button and an exterior coating of button and terminating short of the support means.

overheating or is a continuation-in-part of I an arbor enclosed therein and having a butheat-reflecting material applied to the 2. In an incandescent electric lamp, a bulb, an

arbor supported in said bulb and terminating in a button, support means extending from said and a coating of heat-reflecting material applied to said button and terminating short of said support means.

3. In an incandescent electric lamp, a bulb, a flare tube'sealed therein and having a press, a lead-in conductor supports extending through said press, an arbor extending irom said press between said supports and terminating in a button, wires extending from said button, a, filament extending from one conductor support to the other, with intermediate portions supported by said wires, and a coating of heat reflecting material on the exterior of said button and terminatin: short. of saidwires.

a filament carried by said support means,

in conductor supports extending through .said press, a glass arbor extending irom said press between said supports and terminating in a button, relatively short filament supports extending from said button and formed with end loops, a filament extending irom one conductor support to another through said loops, and a coating of aluminum paint on said button between, and terminating short of. the points of connection of the filament supports therewith.

5. A mount for an incandescent electric lamp comprising a flare tube, lead-in conductor supports extending therefrom, an arbor extending iromsaid flare tube and disposed between said supports, a filament the ends of which are connected to said supports, means extending from the end portion of said arbor and supporting intermediate portions of said filament, and a heat reflecting coating applied to said end portion and terminating "short of said supporting means.v

' 6. A mount for an incandescent electric lamp comprising a flare tube having a press, lead-in conductor supports extending through said press, an arbor extending from said press between said supports and terminating in a button, relatively short filament supports extending from said button, a filament extending from one conductor support to the other and with intermediate portions resting on said supports, and a coating ofaluminum paint on said button, but terminating short of said supports.

'7. The method or manufacturing an incandescent electric lamp comprising supporting an incandescible filament adjacent the end of an arbor, coating the arbor end portion with a heatreflecting material spaced from the filament,-

supporting means, and sealing said mount into a b b.

8. The method of manuiacturing an incandes- 'cent electric lamp comprising supporting the filament from wire supports extending from a button on the end 01' an arbor, coating said button with aluminum paint between the points of union of said supports therewith, but terminating short oi said supports, sealing said mount into a bulb,

and surrounding the filament with an inert gas.

Y ANLEY ST H. NEWTON. 

